Block system for tramways.



D. D. SAMAIA. BLOCK SYSTEM FOR TRAMWAYS.

APPLIUATION FILED SEPT. 29, m1.

1, 1 08,084. Patented Aug. 18, 1914,

2 SHEETS-SHEET l.

D. D.v SAMAIA. BLOCK SYSTEM FOR TRAMWAYS. APPLIOATION FILED SEPT. 29,1911.

1,108,084. Patented Aug. 18, 1914.

niet .vo/ams PEIERS cu v IHom L/THU '.vArmlNbmN. 11 1 DINO DAVIDESAMAIA, OF MILAN, ITALY.

BLOCK SYSTEM FOR TRAMWAYS.

Specification of Letters Patent.

Patented Aug. 18, 1914.

Application ledseptember 29, 1911. Serial No. 651,950.

To all LU/Lomi t may concern.'

Be it known that I, DINO DAVIDE SAMAIA, a subject of the King of Italy.residing at 11 Via Caradosso, Milan, Italy, have invented a certain newand useful Block System for Tramways, of which the following is aspecification.

The present invention has for its object a block system for tramwaylines which is of'very simple construction, and which assures greatsecurity in operation. Y

The principal characteristics of this system are 1. That a certainnumber of cars having entered the single track an equal number mustleave before the semaphore will give the signal for line clear. 2. Thatin the case where two cars following each other on the same line arriveat the same instant, one at the point of entry on the single track andthe other at the point at which the single track is left the workingremains suspended, the semaphore remaining in the position whichindicates that the line is blocked, and which is determined bythe'passage of the first car. 3. That when a car has by mistake passedon to the single track and must be drawn back on to the double track thesemaphores will be brought back into the same position as they werebefore the car moved on to the single track.

In the accompanying drawing. which represents a constructional form ofthe invention; Figure 1 is a view of the general arrangement. Fig. 2shows the device for taking current from overhead. Fig. 3 isa frontelevation of the signaling device and Fig. 4 is a side view of the samearrangement.

As will be seen from Fig. 1, the system comprises four devices fortaking current, 1, 2, 3, 4, (two for cars passing in one direction, andtwo for cars passing in the other direction,) provided on the trolleywire: two semaphores 5 and 6 which may be fixed to the wall or better,suspended in the middle of the track.

. Each device for taking current (Fig. 2) is constituted by a movableyoke or frame 8 through which passes the trolley wire 9. This yoke ishinged to levers 10, 10 which are pivoted at 11, 11 to the cover 12. Atthe point at which they are pivoted to the yoke 8, the levers 10, 10 areprovided with projections 13, 13'.. Rods 14 14 are so providedas to becapable of slidingin the oilinterrupters 15, 15. Each of theseinterrupters (see the part in section in Fig. 2) comprises copper blades16, connected at their upper ends to the rod of the interrupter, and thelower extremities of which dip into the oil. The spring 17 normallypresses the rod 14 downward so as to break the contact of the blades 16with the metallic walls of the interrupter.

The signaling device (Figs. 3 and 4) cornprises essentially a screwedshaft 18, provided with a longitudinal groove 19, this shaft passingthrough wheels 20, 21, which are mounted on the double support 22. Thehub ofthe wheel 20 is provided in the interior with a nut adapted togear with the threads of the shaft 18, while in the interior of the hubof the wheel 21 is fixed a key which can slide along 'the groove 19 ofthe shaft 18.

Thevwheels 20, 21 each carry four pins which during the operation of thedevice are engaged by toothed levers 23, 24, which are connectedrespectively to the rods of the solenoids 25, 26.

The signaling disk 27 is carried by a shaft 28 which is normally held insuch a position by a spring 32 that the disk 27 indicates that the lineis blocked. To the upper extremity of the shaft 28 is keyed a crank 29.`This crank 29 is in its turn connected to a lever 30 connected to onearm of a bell crank lever 31, pivotally suspended at 31, the other armof said bell crank lever being in contact with the end of the screwedshaft 18.

The circuits from the separate devices 1, 2 3 and 4 for taking currentto the semaphores 5 and 6 are as follows: The circuits of the device 1consists of the terminal 15, the conductor 1", the magnet 25 of thesemaphore 6, y

and the magnet to earth; the terminal 151, the conductor 1* the magnet26 of the semaphore 6, and the magnet to earth. The circuits of thedevice 2 consist of the terminal 151, the conductor 2b, the magnet 26 ofthe semaphore 6, and themagnet to earth; the terminal 15, the conductor2, the magnet 25 of the semaphore 6, and the magnet to earth.

Of the device 3 the circuits consist of the terminal 151, the conductor3*, the magnet 26 of the semaphore 5, and the magnet to earth, theterminal 15, the conductor 3b, the magnet 25 of the semaphore 5, and themagnet to earth.

The two circuits of the device 4 consist of the terminal 15, theconductor 4a, the magnet 25 of the semaphore 5, and the magnet to earth;and the terminal 151, the conductor 4th, the magnet 26 of the semaphore5, and the magnet to earth.

The connection of the magnets to earth is effected in any known manner.

The arrangement works in the following manner z-The roller of thetrolley of the car, on coming into contact with the movable yoke 8 ofthe device for taking current (Fig. 2) raises it, and the lever 10 isrotated around the point 11. In `consequence of this the projection 13bears against the extremity of the rod 14 of the interrupter 15, andpushes this rod upward so that the blades 16 establish a metallicconnection in the interrupter 15 which allows current to iow. Thiscurrent is conducted as required either to the electrofmagnet 25 whichis intended to effect the signal that the line is blocked or to theelectro-magnet 26 which is intended to effect the signaling of lineclear. In Fig. 3 is shown the signal for line vclear the disk 27 beingturned edgewise; the disk is held in this position by the pressureexercised by the shaft 18 against the end of the lever 31', ythispressure overcomi-ng the strength of the spring 32.

Supposing that a car enters the single track and that the device fortaking current for signaling that the line is blocked is operated by thetrolley of this car, the current will excite the electro-magnet 25. Thelatter will raise the lever 23 which engages one of the pins of thewheel 2O and will cause this wheel to rotate a quarter of Ia turn; owingto'this rotation ofthe wheel 2O and of the engagement of the nutprovided in the hub of the wheel with the threads of the shaft 18, thelatter which is held by the key of the wheel 21 (the `motion of thiswheel being arrested in its turn bythe lever 24) is displacedlongitudinally a distance 'of a centimeter from the left toward theright. In consequence of this displacement, the shaft 1-8 ceases topress against the head of the lever 31, and the spring 32 then begins tooperate, rotating the 'shaft 28 and consequently the disk 27, into theposition represented by dotted lines in Fig. 3, that is to say, into theposition corresponding to the signal thatl the line is blocked. Let ussuppose now that it is required to give the signal for line clear Thedevice for takingcurrent being operated by the trolley Q of the car, thecurrent'is made tol excite the electro-magnet 26 and thus raise .theleverl 24, the projection on which engages one of the pins of the wheel21 causing it to rotate through a quarter turn. The rotation of the`wheel 21 causes, by'means of the key already j mentioned, rotationofthe screwed shaft A18, l which, since it engages with the nut pro`vided in the hub ofthe wheel 2()k is consei quently displacedlongitudinally to the extent of one centimeter from the right to theleft. The shaft 18 therefore contacts again with the end of the lever 31and the system 31, 30, 29 is so operated as to overcome the resistanceof the spring 32, and to turn the shaft 28 and the disk 27 into theposition for signaling line clear. In the same manner, if, instead ofone car, three cars for example, enter the single track, the wheel 2Owill be rotated three quarters of a turn and the shaft 18 will bedisplaced from the left toward the right to the extent ,of threecentimeters. In order to signal line clear it will therefore benecessary to displace the said shaft 18 three centimeters in theopposite direction, that is to say, the wheel 21 must be rotated threequarters of a turn which corresponds to the exit of three cars. In oneword if a certain number of cars are on the single track, an equalnumber should leave in order that the semaphore shall give the signalline clear This arrangement also has the advantage that if two cars,following each other on the same line, arrive at the same instant, oneat the point of entry on the single track and the other at the point atwhich the single track is left, the working remains suspended. In fact,in this case since the wheels 20, 21 turn simultaneously, their actionon the screwed shaft 18 is reciprocal and equal and therefore the shaftwill turn without being displaced in one direction or in the other.

In order to obviate the inconveniences which arise in the case when acar having 'passed the point at whichthe single track Vis left must bedrawn back, onto the single track, the devices for taking current areprovided with two oil interrupters, one of which operates when the lineis blocked, the other when the line is cleared. As will be seen in Fig.2 the communication with these interrupters is established respectivelyby the projections 13, 13 of the levers 10, 10. Owing to thisarrangement, each time that a car is drawn back, for any reason, afterhaving operated the interrupter which is intended for signalingv lineclear, the moving back will have for its effect to determine the actionof the other interrupter in the opposite direction, so aslto suspend thesignaling of line clear. This signal will only be made again when theear again leaves the single track. The same applies for the kcase when acar having passed the point of entry on the single track and determinedthe action ofthe blocking device, is for any reason moved back.

What I claim is 1. The combination with a block system for tramways of asignaling device comprising two magnets, cores operated by said magnets,wheels adapted to be rotated by said cores, a screwed shaft having a keyWay and passing through said wheels, one of said wheels having a screwthread corresponding to the screw on the shaft, a key in the other wheelengaging with the key way of the shaft, a semaphore, means connectingthe semaphore to the screwed shaft, and means for energizing themagnets.

2. The combination with a block system for tramways of a signalingdevice comprising two magnets, cores operated by said magnets, wheelsadapted to be rotated by said cores, a screwed shaft having a key wayand passing through said wheels, one of said wheels having a screwthread corresponding to the screw on the sha-ft, a key in the otherwheel engaging with the key way of the shaft, a semaphore, meansconnecting the semaphore to the screwed shaft, and means for energizingthe magnets, said means comprising two interrupters of which one closesthe circuit for one magnet and the other closes the circuit for theother magnet when operated by a car moving onto or off the single track.

3. The combination in a block system for tramways of a screwed shafthaving a key way, two wheels mounted on said shaft, one of said wheelshaving an internal screw thread corresponding to the thread of theshaft, a key in the other wheel corresponding to the key way in thescrewed shaft, pins on said wheels, magnets, cores, said cores engagingwith said pins, a rotary shaft, a semaphore mounted on said shaft, meansadapted to retain the rotary shaft in the normal position, and meansconnecting the rotary shaft to the screwed shaft.

In testimony whereof I aIiX my signature in presence of two witnesses.

DINO DAVIDE SAMAIA.

Witnesses ALBERT PERI, GIRUEP GRIFFE.

Copies of this patent may be obtained for ive cents each, by addrelsingthe Commissioner ot latents, Washington, D. C.

